Patent Application
20060083579
1. Field of the Invention
The present invention relates to a writing implement with a stylus, such as a ballpoint pen provided in its back end part with a stylus that is projected by a rotary device or a mechanical pencil provided in its back end part with a stylus that is projected by a rotary device.
2. Description of the Related Art
Some conventional writing implement is provided with an unretractable stylus having an exposed tip and some other conventional writing implement is provided with an unretractable stylus having a tip covered with a cap. It is possible that the tip of the stylus of the former writing implement accidentally scratches or pricks something. The latter writing implement requires a trouble to remove the cap to use the stylus and it is possible that the cap is lost. A writing implement proposed in JP-A 2002-62976 is provided with a writing member and a stylus and enables setting either of the writing member and the stylus at its working position for the selective use of the writing member or the stylus. However, both the writing member and the stylus cannot be set at their working positions simultaneously.
The stylus having a sharp tip needs to be covered while the stylus is not used. However, considerable effect is required to remove the cap because the cap is held on a barrel by a holding structure and considerable force is necessary to release the cap from the barrel. There has not been any writing implement provided with a writing member and a stylus that can be individually projected from and retracted into the barrel of the writing implement.
The present invention has been made in view of the foregoing problems and it is therefore an object of the present invention to provide a writing implement provided with both a writing member and a stylus held in a barrel and capable of being simultaneously or selectively projected from the barrel for use.
A writing implement according to the present invention includes: a barrel provided with a separate front cap or a front cap formed integrally with the barrel; a writing member placed in the barrel, pushed constantly backward by a return spring and capable of axially sliding in the barrel when a push button is operated; and a stylus mechanism including a stylus that can be projected by turning the push button.
The writing implement of the present invention is simple in construction, the writing member, such as a lead, can be projected and retracted by operating the push button, and the stylus can be surely projected and retracted by turning the push button. Thus, both the writing member and the stylus can be simultaneously kept projected, and either of the writing member and the stylus can be selectively used without requiring any additional operations.
The above and other objects, features and advantages of the present invention will become more apparent from the following description taken in connection with the accompanying drawings, in which:
A sliding mechanism that slides longitudinally on the barrel 1 will be described. The ballpoint refill 4 inserted in the barrel 1 is axially movable in the barrel 1. A return spring 5 applies a resilient force constantly to the ballpoint refill 4 to push the ballpoint refill 4 backward. The ballpoint refill 4 has a tip 42 at its front end. A spring retaining part 41 is formed on the outer surface of a front part of the ballpoint refill 4. The return spring 5 is extended between the spring retaining part 41 and the front cap 2. The back end of the ballpoint refill 4 is received in a cam part 61 of the rotating cam 6. The cam part 61 of the rotating cam 6 has a cam follower engaged in the cam groove 35 of the back cap 3, and a toothed part engaged with a front toothed part 72 of the plunger 7. The rotating cam 6 is inserted in the plunger 7.
Referring to FIGS. 6 to 9 showing the plunger 7, the plunger 7 has the front toothed part 72 engaged with the upper end of the cam part 61 of the rotating cam 6, and an externally threaded part 71 provided with a double thread. Recessing undercut parts near a parting line facilitate molding. When the depth of back end parts of the external thread of the externally threaded part 71 is reduced slightly to increase frictional resistance against the movement of an internally threaded part 83 of the stylus 8 relative to the externally threaded part 71, a braking force acts on the push button 9 when the push button 9 is turned to a position near the limit of turning of the push button 9 to improve operating feeling.
The plunger 7 has flat ribs 73 having a pointed front end spaced a short distance apart from the toothed part 72. When the tip of the stylus 8 projects through an opening 91 formed in the back end of the push button 9 as shown in
Referring to FIGS. 10 to 13, the hollow stylus 8 having a tip part 82 is screwed on the externally threaded part 71 of the plunger 7. An internal double thread is formed in internally threaded part 83 of the inner surface of the stylus 8. The cylindrical push button 9 is put on the stylus 8. The push button 9 is able to turn on the stylus 8. The stylus 8 has a body part 81 of a large diameter, and the tip part 82 extending from the body part 81. The body part 81 has the internally threaded part 83 provided with the internal double thread, and diametrically opposite longitudinal guide ribs 84 on its outer surface. The guide ribs 84 are provided with protrusions 85, respectively. A pair of slits 86 are formed in the body part 81 so as to extend longitudinally from front end of the body part 81.
Referring to FIGS. 14 to 18, the push button 9 is a hollow, cylindrical member provided with the opening 91 at its back end. The stylus 8 is projected from and retracted into the push button 9 through the opening 91. Through holes 92 are formed diametrically opposite to each other in the side wall of the push button 9. A longitudinal stylus guide groove 93 is formed in the inner surface of the push button 9 so as to extend backward from a part near the open front end of the push button 9. A front end part of the stylus guide groove is flared toward the open end thereof. When necessary, teeth may be cut in the outer surface of the push button 9 by knurling to increase friction.
An assembling procedure for assembling the ballpoint pen, namely, a writing implement with a stylus, in the preferred embodiment will be described to facilitate understanding the construction of the ballpoint pen. The stylus 8 and the plunger 7 are combined in an assembly by engaging the internally threaded part 83 of the stylus 8 and the externally threaded part 71 of the plunger 7. The assembly is inserted in the push button 9 to form a push button assembly. The push button assembly is combined with the back cap 3 to form a back cap assembly. The return spring 5 is put in the barrel 1, the ballpoint refill 4 is inserted in the barrel 1 and the back cap assembly is attached to the barrel 1 to complete the ballpoint pen.
The operation of the ballpoint pen will be described. When the ballpoint pen is used as a writing implement for writing, the push button 9 is pushed to advance the stylus 8, the plunger 7 and the rotating cam 6 against the resilience of the return spring 5. The rotating cam 6 engages with the ballpoint refill 4 as the same is advanced to advance the ballpoint refill 4. Since the cam part of the rotating cam 6 is engaged in the cam groove 35 of the back cap 3, the rotating cam 6 rotates as the same is advanced. The rotating cam 6 is stopped at the front end of the cam groove 35. Thus the ballpoint refill 4 is advanced and the tip 42 of the ballpoint refill 4 projects from the front cap 2 through the open front end of the front cap 2 to prepare the ballpoint pen for writing. The push button 9 is pushed again to retract the tip 42 of the ballpoint refill 4 into the barrel 1. When the push button 9 is pushed again, the rotating cam 6 is released from the cam groove 35 of the back cap 3, and the ballpoint refill 4 is pushed backward by the resilience of the return spring 5.
To use the stylus 8 with the ballpoint refill 4 retracted into the barrel 1, the ballpoint pen is held by the barrel 1 or the back cap 3 and the push button 9 is turned in one of opposite directions. Then, since the stopper rib of the stylus 8 is engaged in the stylus guide groove 93 of the push button 9, the stylus 8 turns as the push button 9 is turned. Since the toothed part of the plunger 7 is engaged with and restrained from turning by the back end of the cam part of the rotating cam 6, the stylus 8 screwed on the plunger 7 moves backward and projects through the opening 91 of the push button 9. Thus the stylus 8 is set for use.
The stylus 8 can be thus projected for use even in a state where the tip 42 of the ballpoint refill 4 is projected from the front cap 2 for writing. Even in a state where the push button 9 has been pushed, the stylus 8 can be projected by turning the pushbutton 9. In such a state, the push button 9 is restrained from free backward movement by the engagement of the stopping projection 76 of the plunger 7 with the stopping rib 38 of the back cap 3. In a state where the stylus 8 is projected for use, the ballpoint refill 4 can be advanced by pushing the stylus 8 or the push button 9 to project the tip 42 of the ballpoint refill 4 from the front cap 2. The projected stylus 8 can be retracted into the push button 9 by turning the push button 9 in the other direction.
The ballpoint pen of the present invention, namely, the writing implement, can be operated in the following operating modes.
Mode 1: Tip of the ballpoint refill is projected for writing with the stylus held inside the barrel.
Mode 2: Stylus is projected with the tip of the ballpoint refill retracted into the front cap.
Mode 3: Tip of the ballpoint refill is projected for writing with the stylus projected from the push button.
Mode 4: Stylus is projected from the push button with the tip of the ballpoint refill projected for writing.
Although the invention has been applied to a ballpoint pen, the present invention is applicable to other writing implements including mechanical pencils.
